#计算四个数的平均值：67.5 89.0 12.9 32.2
avg=(67.5 + 89.0 + 12.9 + 32.2) / 4
total = (67.5 - avg)**2 + (89.0 - avg)**2 + (12.9 - avg)**2 + (32.2 - avg)**2
print(total / 3)